Title
Ripeness evaluation of 'Sun Bright' tomato using optical absorption and scattering properties
Date Issued
01 May 2015
Access level
metadata only access
Resource Type
journal article
Author(s)
Michigan State University
Publisher(s)
Elsevier
Abstract
Ripeness is one of the most important factors in determining the processing and eating quality of tomato. The objective of this research was to evaluate the changes of optical absorption and scattering properties in tomatoes during ripening, and develop classification models for grading the ripeness of tomatoes using optical absorption and scattering spectra. Optical absorption (μa) and reduced scattering (μs') coefficients over the spectral region between 500nm and 950nm were measured, using a hyperspectral imaging-based spatially-resolved instrument, for 281 'Sun Bright' tomatoes harvested at six ripeness grades (i.e., 'Green', 'Breaker', 'Turning', 'Pink', 'Light-red', 'Red'). Absorption peak around 675nm decreased consistently with the progression of ripeness, and its mean value for 'Red' tomatoes was almost zero. The reduced scattering spectra, on the other hand, decreased monotonically with the increasing wavelength; the value of μs' also decreased successively from 'Green' to 'Turning', and an opposite trend was observed from 'Pink' to 'Red'. Partial least squares discriminant analysis (PLS-DA) models yielded 92.1%, 84.4%, 92.3%, and 92.1% classification accuracies for the three ripeness grades (i.e., 'Green/Breaker', 'Turning/Pink', and 'Light-red/Red'), when using the full spectra (500-950nm) of μa, μs', μa&μs' and the effective attenuation coefficient (μeff=[3μa(μa+μs')]1/2), respectively. The PLS-DA model using μeff achieved an overall classification accuracy of 88.4% for the six ripeness grades, which was 2.5% and 10.2% better than using the optical parameters of μa and μs' alone. The research demonstrated that the optical absorption and scattering spectra, especially their combinations, are effective for classification of tomato ripeness.
Start page
27
End page
34
Volume
103
Language
English
OCDE Knowledge area
Agricultura
Scopus EID
2-s2.0-84924083774
Source
Postharvest Biology and Technology
ISSN of the container
09255214
Sponsor(s)
Dr. Qibing Zhu and Miss. Chunliu He gratefully acknowledge financial support from the National Natural Science Foundation of China (Grant nos. 61275155 and 61271384 ) and the 111 Project ( B12018 ).
Sources of information: Directorio de Producción Científica Scopus